Tanguisson Point, Guam

Tanguisson Point, Guam is one of the most connected submarine cable landing points in Guam. 6 international cable systems come ashore here, and together they reach 14 other countries across Asia, North America, Oceania and South America. Few landing points on any continent connect directly to as many.

Why cable lands at Tanguisson Point

Its 6 systems give Tanguisson Point direct international reach to Brunei, China, Malaysia and Philippines and beyond (14 countries in all), the role that justified building international cable here rather than routing through an inland neighbour.

Where its cables reach

• Asia-America Gateway (AAG) Cable System and TPU connect it to North America (United States).
• Halaihai connects it to South America (Chile).
• Asia-America Gateway (AAG) Cable System, Australia-Japan Cable (AJC), Proa and TPU connect it to Asia (including Brunei, China, Malaysia, Philippines, Singapore).
• Australia-Japan Cable (AJC), Halaihai, Mariana-Guam Cable, Proa and TPU connect it to Oceania (Australia, Northern Mariana Islands and French Polynesia).

The systems in detail

The roster spans 30 years of build-out, from Mariana-Guam Cable (1997) to Halaihai (2027). Documented capacity and vintage vary across the roster: Asia-America Gateway (AAG) Cable System (20,000 km and in service since 2009), Australia-Japan Cable (AJC) (12,700 km and in service since 2001), Halaihai (17,483 km and in service since 2027), Mariana-Guam Cable (268 km and in service since 1997), Proa (2,891 km and in service since 2026) and TPU (13,470 km and in service since 2026). Facts for every system are on its own cable page.

What the concentration means for resilience

With 6 independent systems, Guam has real redundancy through this point: no single cable cut isolates it from the destinations they share. The exposure is specific: the link to South America rests on a single cable, with no sibling landing alongside it. Because these systems share the same short stretch of coast and shore infrastructure, a localized event at the landing zone can reach far more capacity than the cable count alone suggests. GeoCables tracks each of these systems individually for exactly this reason.

What our monitoring has recorded

GeoCables watches these systems continuously rather than describing them once. Since 2026-03-10 we have logged 122 route anomalies across 68 cable systems worldwide. Five have touched this location's own cables: a 331% round-trip latency spike on Mariana-Guam Cable (2026-04-14, recovered by 2026-04-15), a 138% round-trip latency spike on Asia-America Gateway (AAG) Cable System (2026-04-07, recovered by 2026-04-07), a 171% round-trip latency spike on Asia-America Gateway (AAG) Cable System (2026-04-05, recovered by 2026-04-05), a 219% round-trip latency spike on Asia-America Gateway (AAG) Cable System (2026-04-04, recovered by 2026-04-04) and a 297% round-trip latency spike on TPU (2026-03-29, recovered by 2026-04-04). These were latency events on the systems' wider routes, not outages at the landing itself, and they cleared on their own. This record grows as we detect more, which is the difference between a directory entry and a monitored asset.

Latency, measured

From the GeoCables probe network, best-case round-trip time to Guam endpoints runs about 282 ms from Minsk, about 301 ms from Tbilisi and about 297 ms from Jerusalem. These are paths into Guam from our own vantage points, not a global average, and they shift as operators re-route.

Who depends on it

The largest access networks in Guam sit behind this coastal capacity: Teleguam Holdings, LLC (35.3% of users), Guam Cablevision, LLC. (21.3% of users), GUAMCELL Communications (18.4% of users) and PTI Pacifica Inc. (17.4% of users). See the full national picture for Guam.

In short, Tanguisson Point, Guam carries international traffic for Guam across 6 independent cable systems reaching 14 countries on 4 continents, and GeoCables monitors each of them in real time.